Odd Timing Marks

[Lucky_Lou]

I tried to find the timing marks to highlight them while i have the gearbox off, couldnt make any sense of it when i tried a strobe....any one elses like this and whats the correct position with a strobe, these are the only marks on the flywheel nothing like the Haynes pictures.Its a drilled mark with 10 stamped above it
Lou

[Crossrodes]

Lou, what year is your bike?  I have a '79 and the timing marks are not as the Clymer manual indicates....

I'm looking at my flywheel (in my lap as I type this).  I have one ball bearing which appears to be embedded in the flywheel.  Next to it, about 1/4" away there is a mark with a Z next to it. I think this is used for setting the timing advance at 3500 RPM.  There is a void about 1 1/2" away from the ball bearing (I'm guessing there was a ball bearing in here at one time)  About 1/4" away from it is another mark with a 0 mark.  I'm guessing this is TDC.

Hope that helps.

[Barry]

Lou , This is what my S mark looks like. The line just visible at the top of the window is the part of the OT mark which can look a bit like a 10.

[nhmaf]

It looks like that is the "OT"   (Top Dead Center) mark on the flywheel

[Lucky_Lou]

Mike.....  Its a 79 the mark could be a faded or a poorly stamped "OT" but there is definately no "S" or "Z" any where, those in the photo are the only marks on the outer rim. The timing is ok at the moment so when i rebiuld it ill strobe it to see whats what.
I know its close to TDC as i stuck a screwdriver through the plug hole to feel for it while slowly rotating the engine with an allen key on the generator drive.
Lou

[nhmaf]

There should be an "S" a little ways further - sometimes these are incredibly hard to see.   As your bike is pre-1981, it will most likely have an "F" mark, instead of a "Z" mark, to indicate full advance (which would be quite a bit further in the rotation).  Remeber the "S" mark is only somewhere around 6 degrees BTDC, and full advance is another ~26 degrees or so..

[Crossrodes]

I can say unequivocally that there is no S mark on my flywheel...just an O (or 0) and a Z.  This bike was built for the German market and I'm now wondering if the Z was stamped on the flywheel instead of the S for that market.  Anyone from Europe know this?

[Semper Gumby]

HI Lou/Crossroads.

The "10" mark actually is top dead center on the heavy fly wheel bikes.  It should just be the "0" but perhaps the edge of the stamp caught the flywheel when the hungover technician swung his hammer that morning.

The drilled hole is idle timing mark (6 degrees advance).  There should be a "Z" mark for max advance (32 degrees high speed).  The is no "S" mark on our heavy flywheel bikes -- just the drilled hole.  But then there is no torque setting for the 6 - 6mm bolts that hold the clutch together either.  You just better not use anymore than about 7-10 ft-lbs or you will twist the little heads right off the bolts.  Imagine how much fun that will be.  Things that got left out of the manuals for the two years they made our bikes...  

I have all three of these marks painted with a bit of white out so I can see them when I use the strobe.  Of course since I have the Omega Ignition, I only look at it about once every 15,000 miles or so.... 8-)

When setting the timing with the strobe, the idle hole and the fast "Z" marks should line up with the notch on the viewing hole.  If the Z mark is not there, then you need to clean the flywheel so that you can see it.  It's there.  It may just be covered in crud.

BTW - these idle/fast marks are merely suggestions.  I've had the Idle timing as high as 10 degrees and it works fine.  I've had the fast timing as low as 28 degrees and it works fine.  If you get the mark in sight in the hole then that is good enough.  Don't sweat lining it up with the notch.  

Good luck.

[Crossrodes]

Bill that makes sense to me.  Now here's another question...

I currently have my engine apart.  The pistons were covered in carbon which I have now cleaned.  I had the engine apart about 18 months ago to replace the cylinder base O rings which were leaking oil.  The pistons were covered in carbon then too and I cleaned them up  then.  After I had the engine apart the first time, I went through the tuning process from setting valves, timing, and carbs.  The question is what would be causing this build-up of carbon?  Oh yes, I run the bike with regular gas.

[montmil]

Mike,

Do you do much "high speed" cruising? Carbon buildup can result from daily city putt-puttin' with a slightly rich low-mid range condition.

Perhaps try a different brand of fuel and/or grade. Some folks say Shell gasoline keeps the carbon buildup at bay. I've not tried it myself... nor have I looked too deeply into the cylinders.

[Crossrodes]

Monte I do a little city riding but most of my riding is on the highway.  In the past I used Chevron regularly but because I'm convinced the Chevron dealer is selling something less than a litre for the price of a litre I'll be switching to Shell (I've seen their ads).  I'll have to check in my spark plug holes to see how it's doing.

Mike

[Bob_Roller]

In case you didn't know this, all of the fuel comes from the same source in a large metropolitan area .

All of the tanker trucks regardless of the name on the truck, fill up at the same terminals pumping the same product into the trucks .

An additives package specific to the brand name is then put into the fuel, after it is in the truck .

[Lucky_Lou]

Mistery over i "modified" a wire brush even wth the gearbox off i wasnt making any sense of it, having the gearbox off i cleaned the back rim of the flywheel and lightly sprayed it with white paint left it to dry then re inspected it with a magnifing glass.
The first mark is OT there is a faint "S" throught the  drilled mark and low and behold another drilled mark with a very faint Z about 30 degrees round neither lend them selves to photoing well i wouldnt have found the other marks under the rust without a clue from Semper Gumby..ta
Lou

[nhmaf]

Told ya!!   Gotta have faith - we won't steer you wrong... well, not intentionally, anyway.